Electroconductive layered product, touch panel, and process for producing electroconductive layered product

ABSTRACT

The present invention aims to provide a conductive layered body having excellent solvent resistance and scratch resistance as well as a low haze value and a significantly high light transmittance. The present invention relates to a conductive layered body including, as an outermost layer thereof, a conductive layer containing a conductive fibrous filler, wherein the conductive layered body has a Martens hardness of 150 to 3,000 N/mm 2  as measured at an indentation depth of 100 nm from a surface, and a ratio, in atomic percentage, of a conductive material element constituting the conductive fibrous filler on an outermost surface-side surface of the conductive layer is 0.15 to 5.00 at %.

TECHNICAL FIELD

The present invention relates to conductive layered bodies, touchpanels, and methods of producing conductive layered bodies.

BACKGROUND ART

Transparent, conductive thin films have been used as transparentelectrodes of, for example, displays such as liquid crystal displays(LCDs) and plasma display panels (PDPs), touch panels, and solarbatteries. Examples of such thin films that have been used includetransparent conductive sheets composed of a conductive layer made ofindium tin oxide (ITO) or the like disposed on a glass substrate.

The transparent conductive sheets including glass substrates, however,have poor flexibility. In recent years, therefore, conductive films havebeen primarily used which are produced by forming a conductive layermade of ITO or the like by vacuum deposition or sputtering on asubstrate film made of a flexible resin such as polyester (PET) orpolyethylene naphthalate (PEN).

Unfortunately, the conductive layer made of ITO or the like is notpliable, and thus likely to cause cracking when formed on the substratefilm made of a flexible resin.

In contrast, for example, a known transparent conductor has atransparent conductive layer containing metal nanowire formed on asubstrate (see, for example, Patent Literature 1).

The transparent conductor disclosed in Patent Literature 1 is producedby applying an aqueous dispersion of metal nanowire in a dispersionmedium onto a substrate, preferably onto a hydrophilic polymer layerformed on a substrate, followed by drying to form a transparentconductive layer. In the transparent conductor produced by this method,the metal nanowire is embedded in the substrate or the hydrophilicpolymer layer.

Such a transparent conductor, however, is disadvantageously poor insolvent resistance and scratch resistance because the surface of thesubstrate with the embedded metal nanowire is uncured.

Patent Literature 2, for example, discloses a method of producing atransparent conductive film by forming a transparent conductive layer ona substrate, further forming a cured film on the transparent conductivelayer, and then patterning the transparent conductive layer by etching.Such a method including the formation of a cured film on a transparentconductive layer is expected to improve solvent resistance and scratchresistance.

However, in the transparent conductive film having a cured film on atransparent conductive layer, the cured film on the transparentconductive layer has to be thin because a thick cured layer leads to ahigher surface resistance and to the need for a longer time for etchingthe transparent conductive layer.

Since it is difficult to form thin cured films, polymer materials withgood film forming properties are often particularly selected. Suchpolymer materials with good film forming properties, however, form curedfilms having poor hardness. Even if high-hardness monomers are used, thesmall thickness of the film causes incomplete curing, disadvantageouslyresulting in insufficient scratch resistance.

A method of producing a conductive film by what is called a transferprocess is also known. In the process, a conductive layer is formed on asupport and then transferred to a substrate film (see, for example,Patent Literatures 3 and 4). Such a conductive film is expected to haveimproved solvent resistance and scratch resistance.

For image display devices, however, increasingly higher opticalperformance levels are demanded, so that the conductive films are alsorequired to have excellent optical performance, especially a low hazevalue and a significantly high light transmittance. Conventionalconductive films having conductive layers formed by the transfer processare hardly sufficient in such optical performance.

CITATION LIST Patent Literature

Patent Literature 1: JP 2010-084173 A

Patent Literature 2: JP 2014-188828 A

Patent Literature 3: JP 2009-252493 A

Patent Literature 4: JP 5430792 B

SUMMARY OF INVENTION Technical Problem

In view of the situation in the art, the present invention aims toprovide a conductive layered body having excellent solvent resistanceand scratch resistance as well as a low haze value and a significantlyhigh light transmittance, a touch panel including the conductive layeredbody, and a method of producing a conductive layered body.

Solution to Problem

The present invention is directed to a conductive layered bodyincluding, as an outermost layer thereof, a conductive layer containinga conductive fibrous filler, wherein the conductive layered body has aMartens hardness of 150 to 3,000 N/mm² as measured at an indentationdepth of 100 nm from a surface, and a ratio, in atomic percentage, of aconductive material element constituting the conductive fibrous filleron an outermost surface-side surface of the conductive layer is 0.15 to5.00 at %.

Preferably, the conductive layered body of the present invention has atotal light transmittance of 80% or higher and a haze of 5% or lower.

Preferably, the conductive layer contains a binder resin and has theconductive fibrous filler contained in the binder resin, and part of theconductive fibrous filler protrudes from the outermost surface-sidesurface of the conductive layer.

Preferably, the conductive layer has a thickness smaller than a fibersize of the conductive fibrous filler.

Preferably, the conductive fibrous filler has a fiber size of 200 nm orsmaller and a fiber length of 1 μm or greater.

Preferably, the conductive fibrous filler is at least one selected fromthe group consisting of conductive carbon fibers, metal fibers, andmetal-coated synthetic fibers.

Preferably, in the conductive layered body of the present invention, theconductive layer is on a resin layer.

The present invention is also directed to a touch panel including theconductive layered body of the present invention.

The present invention is also directed to a method of producing aconductive layered body including, as an outermost layer thereof, aconductive layer containing a conductive fibrous filler, the methodincluding a transferring step of transferring the conductive layer to areceiver using a transfer film having at least the conductive layer on arelease film.

In the method of producing a conductive layered body of the presentinvention, preferably, the conductive layered body has a haze value of5% or lower and a total light transmittance of 80% or higher.

Preferably, the conductive layer in the transfer film contains a binderresin and has the conductive fibrous filler contained in the binderresin, and part of the conductive fibrous filler protrudes from asurface of the conductive layer on the side opposite the release film.

Preferably, the conductive layer has a thickness smaller than a fibersize of the conductive fibrous filler.

Preferably, the conductive fibrous filler has a fiber size of 200 nm orsmaller and a fiber length of 1 μm or greater.

Preferably, the conductive fibrous filler is at least one selected fromthe group consisting of conductive carbon fibers, metal fibers, andmetal-coated synthetic fibers.

Preferably, the method further includes a treatment step of subjectingthe conductive layer to ultraviolet irradiation and/or heating.

Preferably, the receiver is a resin layer.

The present invention will be described in detail below.

The “resin” as used herein includes a monomer, an oligomer, and apolymer, if not otherwise specified.

The present invention is directed to a conductive layered bodyincluding, as an outermost layer thereof, a conductive layer containinga conductive fibrous filler.

The present inventors made intensive studies to find out the following:The conductive layered body including, as an outermost layer thereof, aconductive layer containing a conductive fibrous filler can haveexcellent solvent resistance and scratch resistance as well as a lowhaze value and a significantly high light transmittance when the surfacehardness is within a predetermined range and the conductive materialelement constituting the conductive fibrous filler is present at apredetermined ratio on the outermost surface-side surface of theconductive layer. The inventors thus completed the present invention.

The conductive layered body of the present invention has a Martenshardness of 150 to 3,000 N/mm² as measured at an indentation depth of100 nm from a surface. The “surface” means the outermost surface of theconductive layered body of the present invention on the conductive layerside.

If the Martens hardness is smaller than 150 N/mm² as measured at anindentation depth of 100 nm from the surface, the conductive layeredbody of the present invention is easily scratched in the productionprocess. If the Martens hardness is greater than 3,000 N/mm², theetching rate may be reduced, or the problem of cracking in bending ismore likely to occur. The lower limit of the Martens hardness asmeasured at an indentation depth of 100 nm from the surface ispreferably 200 N/mm², and the upper limit thereof is preferably 1,000N/mm². The lower limit is more preferably 250 N/mm², and the upper limitis more preferably 500 N/mm².

The “Martens hardness” as used herein is the Martens hardness measuredat an indentation depth of 100 nm from the surface using anultramicrohardness measuring system “PICODENTOR” produced by Fischer.

The conductive layered body of the present invention preferably has ahigh Martens hardness at a position closer to the outermost surface.Specifically, the conductive layered body preferably has a Martenshardness of 1,000 to 40,000 N/mm² as measured at an indentation depth of5 to 10 nm from the surface. With such a Martens hardness, even afterresistance tests such as a solvent resistance test or a scratchresistance test are conducted on the conductive layered body of thepresent invention, the scratch resistance and solvent resistance beforethe resistance tests are more likely to be maintained. The conductivelayered body of the present invention preferably has a Martens hardnessof 20 to 1,000 N/mm² as measured at an indentation depth of 500 to 1,000nm from the surface. Such a Martens hardness leads to a good hardnessbalance of the entire conductive layered body of the present invention,making it easy to improve the characteristics of the conductive layeredbody of the present invention such as the etching rate or adhesiveness.The “indentation depth of 500 to 1,000 nm from the surface” means adepth below the interface between the conductive layer and a lower layerformed on the side opposite the outermost surface-side surface of theconductive layer, that is, a depth on the lower layer side.

In some production methods, solvents or some resin components can bedissolved and penetrate the lower layer of the conductive layered bodyof the present invention. If this makes the lower layer too much softerthan the Martens hardness of the conductive layer, the indentation depthfrom the surface may be affected by the physical properties. It is thusmore preferred that the Martens hardness balance of the entireconductive layered body of the present invention is within anappropriate range with respect to the Martens hardness at an indentationdepth of 100 nm from the surface.

The conductive layer contains a conductive fibrous filler.

In the present invention, the conductive layer may contain a binderresin in addition to the conductive fibrous filler. In this case,preferably, part of the conductive fibrous filler protrudes from theoutermost surface-side surface (hereinafter also referred to simply as a“surface”) of the conductive layer.

The conductive layered body having such a conductive layer can have alow haze value and a high light transmittance.

Furthermore, when the conductive fibrous filler is contained in thebinder resin, the conductive layer can have particularly excellentscratch resistance.

Any binder resin may be used. For example, the binder resin ispreferably transparent. For example, the binder resin is preferably acured product obtained by curing an ionizing radiation-curable resin byultraviolet irradiation or electron beam irradiation. The ionizingradiation-curable resin is a resin that can be cured by irradiation withultraviolet light or electron beam.

The ionizing radiation-curable resin may be a compound having one or twoor more unsaturated bonds. Examples thereof include compounds havingacrylate functional groups. Examples of compounds having one unsaturatedbond include ethyl (meth)acrylate, ethylhexyl (meth)acrylate, styrene,methylstyrene, and N-vinylpyrrolidone. Examples of compounds having twoor more unsaturated bonds include polyfunctional compounds such astrimethylolpropane tri(meth)acrylate, tripropylene glycoldi(meth)acrylate, diethylene glycol di(meth)acrylate, dipropylene glycoldi(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritoltetra(meth)acrylate, dipentaerythritol hexa(meth)acrylate,1,6-hexanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate,trimethylolpropane tri(meth)acrylate, ditrimethylolpropanetetra(meth)acrylate, dipentaerythritol penta(meth)acrylate,tripentaerythritol octa(meth)acrylate, tetrapentaerythritoldeca(meth)acrylate, isocyanuric acid tri(meth)acrylate, isocyanuric aciddi(meth)acrylate, polyester tri(meth)acrylate, polyesterdi(meth)acrylate, bisphenol di(meth)acrylate, diglycerintetra(meth)acrylate, adamantyl di(meth)acrylate, isobornyldi(meth)acrylate, dicyclopentane di(meth)acrylate, tricyclodecanedi(meth)acrylate, and ditrimethylolpropane tetra(meth)acrylate. Suitableamong them are pentaerythritol triacrylate (PETA), dipentaerythritolhexaacrylate (DPHA), and pentaerythritol tetraacrylate (PETTA). The“(meth)acrylate” as used herein refers to methacrylate and acrylate. Inthe present invention, the ionizing radiation-curable resin may be oneobtained by modifying any of the above compounds with PO, EO, or thelike.

Examples of resins usable as the ionizing radiation-curable resin otherthan the above compounds include polyester resin, polyether resin,acrylic resin, epoxy resin, urethane resin, alkyd resin, spiro-acetalresin, polybutadiene resin, and polythiol-polyene resin, which have anunsaturated double bond and a relatively low molecular weight

The ionizing radiation-curable resin may be used in combination with asolvent drying-type resin (a resin such as a thermoplastic resin, thatcan be formed into a coating film by simply drying the solvent addedbefore application for adjustment of the solids content). The combineduse with the solvent drying-type resin effectively prevents defectivecoating on the surface to which the coating solution is applied informing the conductive layer.

Any solvent drying-type resin may be used in combination with theionizing radiation-curable resin. A thermoplastic resin can be generallyused.

Any thermoplastic resin may be used. Examples thereof include styreneresins, (meth)acrylic resins, vinyl acetate resins, vinyl ether resins,halogen-containing resins, alicyclic olefin resins, polycarbonateresins, polyester resins, polyamide resins, cellulose derivatives,silicone resins, and rubbers and elastomers. The thermoplastic resin ispreferably amorphous and soluble in organic solvents (in particular,common solvents capable of dissolving multiple polymers or curablecompounds therein). From the standpoint of transparency and weatherresistance, preferred thermoplastic resins include styrene resins,(meth)acrylic resins, alicyclic olefin resins, polyester resins, andcellulose derivatives (e.g., cellulose esters).

The conductive layer may contain a thermosetting resin. Anythermosetting resin may be used. Examples thereof include phenolicresin, urea resin, diallyl phthalate resin, melamine resin, guanamineresin, unsaturated polyester resin, polyurethane resin, epoxy resin,aminoalkyd resin, melamine-urea co-condensation resin, silicon resin,and polysiloxane resin.

The conductive layer containing the binder resin may be formed by, forexample, applying to a substrate film (described later) a compositionfor a conductive layer containing the conductive fibrous filler, themonomer component of the ionizing radiation-curable resin, and asolvent, drying the composition to form a coating film, and curing thecoating film by ionizing radiation irradiation.

Examples of the solvent contained in the composition for a conductivelayer include alcohols (e.g., methanol, ethanol, propanol, isopropanol,n-butanol, s-butanol, t-butanol, benzyl alcohol, PGME, ethylene glycol),ketones (e.g., acetone, methyl ethyl ketone, methyl isobutyl ketone,cyclohexanone), ethers (e.g., dioxane, tetrahydrofuran), aliphatichydrocarbons (e.g., hexane), alicyclic hydrocarbons (e.g., cyclohexane),aromatic hydrocarbons (e.g., toluene, xylene), carbon halides (e.g.,dichloromethane, dichloroethane), esters (e.g., methyl acetate, ethylacetate, butyl acetate), cellosolves (e.g., methyl cellosolve, ethylcellosolve), cellosolve acetates, sulfoxides (e.g., dimethyl sulfoxide),and amides (e.g., dimethylformamide, dimethylacetamide). Mixturesthereof may be used.

The composition for a conductive layer preferably further contains aphotopolymerization initiator.

The photopolymerization initiator is not limited, and may be a knownpolymerization initiator. Specific examples thereof includeacetophenones, benzophenones, Michler's benzoyl benzoate, α-amyloximeester, thioxanthones, propiophenones, benzyls, benzoins, andacylphosphine oxides. The photopolymerization initiator is preferablymixed with a photosensitizer. Specific examples thereof includen-butylamine, triethylamine, and poly-n-butylphosphine.

When the resin component contained in the composition for a conductivelayer is a resin having a radically polymerizable unsaturated group, thephotopolymerization initiator is preferably one or a mixture of two ormore of acetophenones, benzophenones, thioxanthones, benzoin, benzoinmethyl ether, and the like. When the resin component is a resin having acationically polymerizable functional group, the photopolymerizationinitiator is preferably one or a mixture of two or more of aromaticdiazonium salts, aromatic sulfonium salts, aromatic iodonium salts,metallocene compounds, benzoinsulfonic acid esters, and the like.

In the composition for a conductive layer, the photopolymerizationinitiator content is preferably 0.5 to 10.0 parts by mass relative to100 parts by mass of the resin component. If the photopolymerizationinitiator content is less than 0.5 parts by mass, the conductive layerto be formed may have an insufficient hardness. If thephotopolymerization initiator content is more than 10.0 parts by mass,the photopolymerization initiator can inhibit curing.

The raw material content (solids content) of the composition for aconductive layer is not limited, but is typically 5 to 70% by mass,particularly preferably 25 to 60% by mass.

According to the purposes such as an increase in the hardness of theconductive layer, a reduction in curing shrinkage, or control of therefractive index, the composition for a conductive layer may containconventionally known additives such as a dispersant, a surfactant, anantistatic agent, a silane coupling agent, a thickener, a discolorationinhibitor, a colorant (pigment, dye), a defoamer, a leveling agent, aflame retardant, a ultraviolet absorber, a tackifier, a polymerizationinhibitor, an antioxidant, or a surface modifier.

Preferred leveling agents include silicone oil and fluorine-basedsurfactants because they prevent the curable resin layer from having aBénard cells structure. When a resin composition containing a solvent isapplied and dried, a surface tension difference occurs between thesurface and the inside of the coating film, and this causes manyconvection currents in the coating film. The structure formed by thisconvection is called Bénard cell structure. The Bénard cell structurecauses problems on the resulting conductive layer such as orange peel ordefective coating.

The composition for a conductive layer may be prepared by any methodthat allows uniform mixing of the components. For example, thecomposition can be prepared with a known device such as a paint shaker,a bead mill, a kneader, or a mixer.

The composition for a conductive layer may be applied to the substratefilm by any method. For example, a known method may be used such as spincoating, dipping, spraying, die coating, bar coating, roll coating,meniscus coating, flexo printing, screen printing, or bead coating.

In curing the dried coating film, the ionizing radiation irradiation maybe conducted using a light source such as an ultra high pressure mercurylamp, a high pressure mercury lamp, a low pressure mercury lamp, acarbon-arc lamp, a black light fluorescent lamp, or a metal halide lamp.

The wavelength of ultraviolet light may be in the range of 190 to 380nm. Specific examples of the electron beam source include electron beamaccelerators such as Cockcroft-Walton accelerators, Van de Graaffaccelerators, resonance transformer accelerators, insulated coretransformer accelerators, linear accelerators, Dynamitron accelerators,and high-frequency accelerators.

When the conductive layer contains the binder resin, the cured productof the binder resin (hereinafter also referred to as a “binder resinlayer”) in the conductive layer preferably has a thickness smaller thanthe fiber size of the conductive fibrous filler. If the thickness of thebinder resin layer is equal to or greater than the fiber size of theconductive fibrous filler, an increased amount of binder resin entersthe contact points between fibers forming the conductive fibrous filler,thus deteriorating the continuity of the conductive layer. This mayprevent the conductive layered body of the present invention fromachieving the target resistance value.

Specifically, the thickness of the binder resin layer is preferably 200nm or smaller. If the thickness of the binder resin layer is greaterthan 200 nm, the fiber size of the conductive fibrous filler has to begreater than the appropriate range described later. Such a fiber sizemay lead to an increase in the haze of the conductive layered body and areduction in the total light transmittance. The thickness of the binderresin layer greater than 200 nm is thus optically unsuitable.

The thickness of the binder resin layer is more preferably 50 nm orsmaller, still more preferably 30 nm or smaller.

When the conductive layer does not contain the binder resin, theconductive layer consists of the conductive fibrous filler. In a crosssection of the layer in the thickness direction, there are thus observedportions with conductive fibrous filler and portions without anyconductive fibrous filler. The portions with the conductive fibrousfiller can include portions where the fibers forming the conductivefibrous filler exist singly, and portions where two or more fibersforming the conductive fibrous filler are stacked on top of one another.However, because of the presence of the portions without any conductivefibrous filler (i.e., portions with a thickness of 0 nm), the thicknessof the conductive layer not containing the binder resin as measured inaccordance with the definition below is also usually smaller than thefiber size of the conductive fibrous filler.

The thickness of the conductive layer can be determined as follows. Across section of the conductive layer is observed using, for example, anelectron microscope such as SEM, STEM, or TEM at a 1,000- to500,000-fold magnification, and the thickness is measured at 10 randomsites. The thickness of the conductive layer is determined as theaverage of the 10 site.

The conductive fibrous filler preferably has a fiber size of 200 nm orsmaller and a fiber length of 1 μm or greater.

If the fiber size is greater than 200 nm, the conductive layered body tobe produced may have a high haze value or an insufficient lighttransmittance. The lower limit of the fiber size of the conductivefibrous filler is preferably 10 nm from the standpoint of theconductivity of the conductive layer. The fiber size is more preferablywithin the range of 15 to 180 nm.

If the fiber length of the conductive fibrous filler is smaller than 1μm, the conductive layer to be formed may have insufficientconductivity. In addition, the conductive fibrous filler may coagulateto cause an increase in the haze value and a decrease in the lighttransmittance. Thus, the upper limit of fiber length is preferably 500μm, and the fiber length is more preferably within the range of 3 to 300μm, still more preferably within the range of 10 to 30 μm.

The fiber size and fiber length of the conductive fibrous filler can bedetermined as follows. The fiber size and the fiber length are eachmeasured at 10 sites using, for example, an electron microscope such asSEM, STEM, or TEM at a 1000- to 500,000-fold magnification. The fibersize and the fiber length each can be determined as the average of the10 sites.

The conductive fibrous filler is preferably at least one selected fromthe group consisting of conductive carbon fibers, metal fibers, andmetal-coated synthetic fibers.

Examples of the conductive carbon fibers include vapor grown carbonfiber (VGCF), carbon nanotube, wire cup, and wire wall. The conductivecarbon fibers may be used alone or in combination of two or morethereof.

Examples of usable metal fibers include fibers produced by a drawingmethod involving drawing stainless steel, iron, gold, silver, aluminum,nickel, titanium, or the like into thin, long fibers, and fibersproduced by a cutting method involving cutting any of such metals. Thesemetal fibers may be used alone or in combination of two or more thereof.

Examples of the metal-coated synthetic fibers include acrylic fiberscoated with gold, silver, aluminum, nickel, titanium, or the like. Thesemetal-coated synthetic fibers may be used alone or in combination of twoor more thereof.

When the conductive layer contains the binder resin, the conductivefibrous filler content is preferably, for example, 20 to 3,000 parts bymass relative to 100 parts by mass of the binder resin. If theconductive fibrous filler content is less than 20 parts by mass, theconductive layer to be formed may have insufficient conductivity. If theconductive fibrous filler content is more than 3,000 parts by mass, theconductive layered body of the present invention may have a high haze oran insufficient light transmittance. In addition, an increased amount ofbinder resin may enter contact points between the fibers of theconductive fibrous filler, thus deteriorating the continuity of theconductive layer. This may prevent the conductive layered body of thepresent invention from achieving the target resistance value. The lowerlimit of the conductive fibrous filler content is more preferably 50parts by mass. The upper limit thereof is more preferably 1,000 parts bymass.

When the conductive layer contains the binder resin, preferably, part ofthe conductive fibrous filler protrudes from the surface of theconductive layer.

As described later, in the case of producing the conductive layered bodyof the present invention by a transfer process using a transfer film,the transfer film is stacked on a receiver with the conductive layerside surface facing the receiver, followed by application of pressure.When the conductive fibrous filler protrudes from the surface of theconductive layer on the side opposite the release film (i.e., thesurface of the conductive layer to be pressed against the receiver), theprotruding conductive fibrous filler is embedded in the receiver intransferring. As a result, the obtained conductive layered body has animproved solvent resistance, which enables suitable formation ofconductive pattern by etching or the like. The obtained conductivelayered body also has excellent scratch resistance.

When the conductive layer contains the binder resin, preferably, part ofthe conductive fibrous filler protrudes from the surface of theconductive layer in the range of 5 to 600 nm. In the present invention,the vertical distance from a flat portion having no conductive fibrousfiller protruding therefrom in the surface of the conductive layer tothe tip of the protruding conductive fibrous filler is preferably withinthe range of 5 to 600 nm. If the vertical distance is smaller than 5 nm,the solvent resistance of the conductive layered body of the presentinvention may not be improved. If the vertical distance is greater than600 nm, the conductive fibrous filler may fall off the conductive layer.The lower limit of the vertical distance is more preferably 10 nm. Theupper limit is more preferably 200 nm.

The vertical distance from the flat portion to the tip of the conductivefibrous filler protruding from the surface of the conductive layer canbe determined as follows. The surface of the conductive layer isobserved by, for example, an electron microscope such as SEM, STEM, orTEM at a 1,000- to 500,000-fold magnification. The vertical distancefrom a flat portion on the surface of the conductive layer to the tip ofthe conductive fibrous filler is measured at 10 sites. The verticaldistance is determined as the average of the 10 sites.

In the conductive layered body of the present invention, the ratio, inatomic percentage, of the conductive material element constituting theconductive fibrous filler on the surface of the conductive layer is 0.15to 5.00 at %. If the ratio is less than 0.15 at %, disadvantages mayarise such as insufficient conductivity of the conductive layered bodyof the present invention or a slow etching rate. If the ratio is morethan 5.00 at %, the conductive layered body of the present invention hasa low light transmittance and also has poor scratch resistance. Thelower limit of the ratio of the conductive material element constitutingthe conductive fibrous filler present on the surface of the conductivelayer is preferably 0.20 at %, and the upper limit is preferably 2.00 at%. The lower limit is more preferably 0.30 at %, and the upper limit ismore preferably 1.00 at %.

The ratio of the conductive material element constituting the conductivefibrous filler present on the surface of the conductive layer can bemeasured by X-ray photoelectron spectroscopy under the followingconditions.

Accelerating voltage: 15 kVEmission current: 10 mAX-ray source: Al dual anodeMeasurement area: 300×700 μmφMeasurement at a depth of 10 nm from the surfaceThe average of three measurements (n=3)

The conductive layer with such a surface preferably has unevenness onthe surface resulting from the conductive fibrous filler, to the extentthat the conductive layered body can achieve solvent resistance andscratch resistance as well as a low haze value and a significantly highlight transmittance.

The conductive layered body of the present invention may be produced byany method that satisfies the above Martens hardness and atomicpercentage. A preferred method includes a transferring step oftransferring the conductive layer to a receiver using a transfer filmhaving at least the conductive layer on a release film. The presentinvention also encompasses such a method of producing the conductivelayered body of the present invention.

In the transferring step, a transfer film having at least the conductivelayer on a release film is used.

The receiver may be any component on which the conductive layer can beformed. Examples thereof include substrates made of any material (e.g.,glass, resins, metals, ceramics) and receiver layers formed on thesesubstrates, such as resin layers and adhesive layers.

The receiver is preferably a resin layer formed on a substrate film onwhich a transparent electrode of, for example, a display (e.g., LCD), atouch panel, or a solar battery is to be formed using the conductivelayer.

In other words, in the conductive layered body of the present invention,the conductive layer is preferably on a resin layer.

The substrate film is not limited. Examples include films of polyesterresins, acetate resins, polyethersulfone resins, polycarbonate resins,polyamide resins, polyimide resins, polyolefin resins, (meth)acrylicresins, polyvinyl chloride resins, polyvinylidene chloride resins,polystyrene resins, polyvinyl alcohol resins, polyarylate resins, andpolyphenylene sulfide resin. Suitable among them are films of polyesterresins, polycarbonate resins, and polyolefin resins.

Other examples of the substrate film include films of amorphous olefinpolymers (cyclo-olefin-polymers: COPs) having alicyclic structures.These are substrates containing norbornene polymers, monocyclic olefinpolymers, cyclic conjugated diene polymers, vinyl alicyclic hydrocarbonpolymers, or the like. Examples thereof include ZEONEX and ZEONOR(norbornene resins) produced by Zeon Corporation., SUMILITE FS-1700produced by Sumitomo Bakelite Co., Ltd., ARTON (modified norborneneresin) produced by JSR Corporation, APEL (cyclic olefin copolymer)produced by Mitsui Chemicals, Inc., Topas (cyclic olefin copolymer)produced by Ticona, and OPTOREZ OZ-1000 series (alicyclic acrylic resin)produced by Hitachi Chemical Co., Ltd.

Preferable alternative substrates for triacetyl cellulose include FVseries (films with a low birefringence and a low modulus ofphotoelasticity) produced by Asahi Kasei Chemicals Corporation.

The substrate film preferably has a thickness of 1 to 100 μm. If thethickness is smaller than 1 μm, the receiver may have insufficientmechanical strength. If the thickness is greater than 100 μm, theconductive film may have insufficient flexibility. The lower limit ofthe thickness of the substrate film is more preferably 20 μm, and theupper limit thereof is more preferably 80 μm. The lower limit is stillmore preferably 40 μm, and the upper limit is still more preferably 60μm.

The surface of the substrate film may be subjected in advance to etchingtreatments such as sputtering, corona discharge, ultravioletirradiation, electron beam irradiation, chemical conversion, oroxidation, or primer treatments. Performing these treatments in advancecan improve adhesiveness to the resin layer to be formed on thesubstrate film. In addition, prior to the formation of the resin layer,the surface of the substrate film may be subjected to dust removal andcleaning by solvent cleaning, ultrasonic cleaning, or the like, ifnecessary.

The transfer film may include any release film. For example, anuntreated polyethylene terephthalate (PET) film is suitably used. Theuntreated PET film has excellent conductive layer releasability aftertransferring the conductive layer to the receiver. It is also lessexpensive than films made of other materials, such as surface-treatedPET films or COP films, thus preventing an increase in the productioncost of the conductive layered body of the present invention.

Examples of the method for transferring the conductive layer to areceiver using the transfer film include a method involving stacking thetransfer film on the receiver with the conductive layer facing thereceiver, applying pressure to the stack, and then removing the releasefilm.

In the method of producing a conductive layered body of the presentinvention, the receiver is preferably a resin layer, as described above.Preferably, after a coating film is formed with a composition for aresin layer having the same formulation as the composition for aconductive layer, the coating film is not completely cured but leftuncured, and the conductive layer is transferred to the uncured coatingfilm as the receiver by the above method, followed by complete curing ofthe uncured coating film by the treatment step.

As described above, in the conductive layer in the transfer film, it ispreferred that part of the conductive fibrous filler protrudes from thesurface on the side opposite the release film, and that the protrudingconductive fibrous filler is embedded in the receiver. When the receiveris an uncured coating film, the conductive fibrous filler can besuitably embedded. Examples of the conductive fibrous filler include thesame conductive fibrous fillers as those described for the conductivelayered body of the present invention.

The conductive layered body of the present invention can be produced bytransferring the conductive layer to the receiver using the transferfilm, but the transfer film may have a coating resin layer, for example,on the surface of the conductive layer on the side opposite the releasefilm, and the conductive layer may be transferred together with thecoating resin layer by the above method using the transfer film. In thiscase, the conductive layer is transferred to the receiver via thecoating resin layer. The coating resin layer is not limited, and may bemade of the same material as the resin layer, for example.

In the conductive layered body of the present invention, the ratio, inatomic percentage, of the conductive material element constituting theconductive fibrous filler on the surface (surface on the side oppositethe release film) of the conductive layer is 0.15 to 5.00 at %; however,when the coating resin layer is formed, the atomic percentage on thesurface of the coating resin layer on the side opposite the conductivelayer is within the above range. To satisfy this atomic percentagerequirement, the coating resin layer needs to be as thin as about 1 to200 nm, for example. The atomic percentage on the surface of theconductive layer thus limits the structure, surface state, and the likeof the coating resin layer or other layer(s) formed on the conductivelayer.

In the method of producing a conductive layered body of the presentinvention, when the conductive layer contains the binder resin, themethod preferably further includes a treatment step of subjecting theconductive layer to ultraviolet irradiation and/or heating. When thetransfer film contains the coating resin layer, the conductive layer maybe subjected to the ultraviolet irradiation and/or heating together withthe coating resin layer in the treatment step. The treatment step allowsthe produced conductive layered body to have more excellentconductivity.

The treatment step may be conducted before or after the transferringstep. Alternatively, the step may be conducted before removing therelease film in the transferring step.

In cases where ultraviolet irradiation is conducted in the treatmentstep, for example, a known flash lamp is preferably used to achieve aconductive layered body having more excellent conductivity. Light from aflash lamp with wavelengths from UV to visible light can intensivelyheat the surface of the conductive layer. Thus, as compared withconventional heat sources, the flash lamp significantly minimizesthermal effect on the layer(s) or substrate film beneath the conductivelayer. In other words, the flash lamp can advantageously instantaneouslyheat only the surface layer.

The ultraviolet irradiation may be conducted under any conditions, butirradiation with ultraviolet light at about 50 to 3,000 mJ is preferred.

In cases where heating is conducted in the treatment step, the heatingis preferably conducted under the conditions of a temperature of 110° C.to 150° C. for about 1 to 30 minutes, for example.

The conductive layered body of the present invention produced in theabove manner has both a low haze value and a high transparency.Specifically, the conductive layered body preferably has a haze value of5% or lower and a total light transmittance of 80% or higher. If thehaze value is higher than 5% or the total light transmittance is lowerthan 80%, the optical performance is insufficient. The upper limit ofthe haze value is preferably 1.5%, more preferably 1.2%. The lower limitof the total light transmittance is preferably 88%, and the lower limitthereof is more preferably 89%.

The haze value is the sum of the internal haze value and the surfacehaze value, and measured in accordance with JIS K-7136 (2000). Themeasurement may be conducted using a reflectance/transmittance measuringdevice HM-150 (Murakami Color Research Laboratory Co., Ltd.), forexample.

The total light transmittance is measured in accordance with JISK-7361-1 (1997). The measurement may be conducted using areflectance/transmittance measuring device HM-150 (Murakami ColorResearch Laboratory Co., Ltd.), for example.

The value of the haze derived from the conductive fibrous filler ispreferably 4% or lower, more preferably 1.5% or lower, still morepreferably 1.0% or lower. The value of the haze derived from theconductive fibrous filler is measured as follows. A sample 0 is preparedby bonding, using optically clear adhesive tape (OCA), glass to bothsides of a film similar to the conductive layer except that it does notcontain the conductive fibrous filler. The haze of the sample 0 ismeasured and taken as H0. A sample 1 is prepared by bonding glass toboth sides of the conductive layer containing the conductive fibrousfiller using OCA. The haze of the sample 1 is measured and taken as H1.The haze determined by calculating H1- H0 is taken as the value of thehaze derived from the conductive fibrous filler.

The glass of the samples for the measurement of the haze value derivedfrom the conductive fibrous filler is 1.1-mm-thick soda glass, and theOCA is OCA 8146-2 (tape thickness: 50 μm) produced by 3M.

The conductive layered body of the present invention has excellentscratch resistance. For example, preferably, no scratch or nosignificant increase in the resistance is observed on the surface of theconductive layer on the side opposite the receiver after waste clothmounted on a jig (1 kg/4 cm²) is reciprocated five times with aGakushin-type rubbing tester on the surface of the conductive layer onthe side opposite the receiver.

The conductive layered body of the present invention can be used as atransparent electrode of, for example, displays such as liquid crystaldisplays (LCDs), and plasma display panels (PDPs), touch panels, andsolar batteries. A touch panel including the conductive layered body ofthe present invention is also encompassed by the present invention.

Advantageous Effects of Invention

The conductive layered body of the present invention has theabove-described structure and thus has a low haze value and asignificantly high light transmittance. The conductive layered body ofthe present invention is therefore suitable for use as a transparentelectrode of, for example, displays such as liquid crystal displays(LCDs) and plasma display panels (PDPs), touch panels, and solarbatteries. The conductive layered body is especially suitable for touchpanels.

The method of producing a conductive layered body of the presentinvention has the above-described features and thus can suitably producea conductive layered body having a low haze value and a significantlyhigh light transmittance.

DESCRIPTION OF EMBODIMENTS

The present invention will be described in more detail below withreference to examples and comparative examples. The present inventionshould not be limited only to these examples and comparative example.

The “part(s)” and “%” herein are based on mass if not otherwisespecified.

EXAMPLE 1 (Production of Transfer Film)

A 50-μm-thick polyester film (A4100, Toyobo Co., Ltd.) was used as arelease film. The composition for a conductive layer described below wasapplied to the untreated surface of the polyester film to 10 mg/m² toform a coating film. The coating film was dried at 70° C. for one minuteand then irradiated with ultraviolet light at UV 50 mJ to form aconductive layer, whereby producing a transfer film.

(Preparation of Composition for Conductive Layer)

A silver nanowire dispersion was prepared by separately conducting thefollowing core forming step and particle growing step using ethyleneglycol (EG) serving as a reducing agent and polyvinylpyrrolidone(PVP:PVP: average molecular weight: 1,300,000, Aldrich) serving as botha morphology controlling agent and a protective colloid agent.

(Core Forming Step)

While stirring 100 mL of EG liquid held at 160° C. in a reactioncontainer, 2.0 mL of a silver nitrate solution (silver nitrateconcentration: 1.0 mol/L) in EG was added at a constant flow rate overone minute.

Subsequently, while holding the mixture at 160° C. for 10 minutes,silver ions were reduced to silver core particles. The reaction solutionwas yellow due to the surface plasmon absorption of nano-sized silvermicroparticles, confirming that the silver ions were reduced to silvermicroparticles (core particle).

Subsequently, 10.0 mL of a PVP solution (PVP concentration: 3.0×10⁻¹mol/L) in EG was added at a constant flow rate over 10 minutes.

(Particle Growing Step)

The reaction solution containing the core particles after the completionof the core forming step was held at 160° C. while stirring, and 100 mLof a silver nitrate solution (silver nitrate concentration: 1.0×10⁻¹mol/L) in EG and 100 mL of a PVP solution (PVP concentration: 3.0×10⁻¹mol/L) in EG were added by a double-jet method at a constant flow rateover 120 minutes.

During this particle growing step, samples of the reaction solution weretaken once every 30 minutes and observed with an electron microscope.The observation showed that the core particles formed in the coreforming step grew into a wire form with time, and no new microparticleswere formed in the particle grown step. An electron micrograph of thefinal silver nanowire was taken, and the particle size in the major axisdirection and that in the minor axis direction were measured on imagesof 300 silver nanowire particles. The arithmetic average was determinedfor each particle size. The average particle size in the minor axisdirection was 100 nm, and the average length in the major axis directionwas 40 μm.

(Desalting/Water Washing Step)

The reaction solution after the completion of the particle growing stepwas cooled to room temperature. The reaction solution was then subjectedto desalting/water washing treatment with an ultrafiltration membranewith a molecular cutoff of 0.2 μm while the solvent was replaced withethanol. Finally, the reaction solution was concentrated to a solutionamount of 100 mL, whereby preparing a silver nanowire dispersion inEtOH.

The obtained silver nanowire dispersion in EtOH was mixed with PET-30(Nippon Kayaku Co., Ltd.), IRGACURE 184 (BASF), and a dilution solventsuch that the silver nanowire concentration was 0.1% by mass, the amountof PET-30 was 0.1% by mass, and the amount of IRGACURE 184 relative toPET-30 was 5%, thus preparing a composition for a conductive layer. Thedilution solvent contained 30% by mass of cyclohexanone.

(Production of Receiver)

A 50-μm-thick polyester film (A4100, Toyobo Co., Ltd.) was used as asubstrate film. A composition for a hard coat layer having theformulation below was applied to the primer-treated surface of thepolyester film to a dried thickness of 2 μm to form a coating film. Thecoating film was dried at 70° C. for one minute to produce a receiverhaving a hard coat layer on the substrate film.

(Composition for Hard Coat Layer)

KAYARAD PET-30 (pentaerythritol triacrylate/pentaerythritoltetraacrylate mixture, Nippon Kayaku Co., Ltd.)30% by massIRGACURE 184 (BASF) 1.5% by massMEK 50% by massCyclohexanone 18.5% by mass

The transfer film was laminated to the receiver with the conductivelayer side of the transfer film in contact with the hard coat layer ofthe receiver. The laminate in the bonded state was then irradiated withultraviolet light (600 mJ) from the transfer film side. The laminate maybe irradiated with ultraviolet light from the receiver side.

The release film was then removed from the transfer film to provide aconductive layered body having the conductive layer transferred to thereceiver.

EXAMPLE 2

A transfer film was produced in the same manner as in Example 1 exceptthat the composition for a conductive layer was applied in an amount of12 mg/m². Thereafter, a conductive film was obtained in the same manneras in Example 1 except that the produced transfer film was used.

EXAMPLE 3

The silver nanowire dispersion in EtOH obtained in Example 1 was mixedwith a dilution solvent to a silver nanowire concentration of 0.1% bymass, whereby preparing a composition 2 for a conductive layer. Thedilution solvent contained 30% by mass of cyclohexanone.

A transfer film was produced in the same manner as in Example 1 exceptthat the composition 2 for a conductive layer was applied in an amountof 12 mg/m². Thereafter, a conductive layered body was obtained in thesame manner as in Example 1 except that the produced transfer film wasused.

EXAMPLE 4

A transfer film was produced in the same manner as in Example 1 exceptthat the composition 2 for a conductive layer was applied in an amountof 15 mg/m². Thereafter, a conductive layered body was obtained in thesame manner as in Example 1 except that the produced transfer film wasused.

EXAMPLE 5

A transfer film was produced in the same manner as in

Example 1 except that the composition 2 for a conductive layer wasapplied in an amount of 25 mg/m². Thereafter, a conductive layered bodywas obtained in the same manner as in Example 1 except that the producedtransfer film was used.

EXAMPLE 6

A transfer film was produced in the same manner as in Example 1 exceptthat the composition 2 for a conductive layer was applied in an amountof 50 mg/m². Thereafter, a conductive layered body was obtained in thesame manner as in Example 1 except that the produced transfer film wasused.

EXAMPLE 7

A transfer film produced in the same manner as in Example 3 and therelease film was removed. The transfer film was further irradiated withultraviolet light (600 mJ) to produce a conductive layered body.

EXAMPLE 8

A transfer film was produced in the same manner as in Example 3. Acomposition for a coating resin layer with the formulation describedbelow was applied to the conductive layer to a dried thickness of 100nm. The applied composition was dried at 70° C. for one minute and thenirradiated with ultraviolet light (10 mJ) to form a coating resin layer,thus producing a transfer film. Thereafter, a conductive layered bodywas obtained in the same manner as in Example 1 except that the producedtransfer film was used.

(Composition for Coating Resin Layer)

KAYARAD PET-30 (pentaerythritol triacrylate/pentaerythritoltetraacrylate mixture, Nippon Kayaku Co., Ltd.)5% by massIRGACURE 184 (BASF) 0.25% by massMEK 70% by massCyclohexanone 24.75% by mass

COMPARATIVE EXAMPLE 1

A transfer film was produced in the same manner as in Example 1 and usedas a conductive layered body without any further treatment.

COMPARATIVE EXAMPLE 2

A transfer film was produced in the same manner as in Example 1. Acomposition for a coating resin layer having the same formulation as inExample 8 was applied to the conductive layer of the transfer film to adried thickness of 30 nm. The applied composition was dried at 70° C.for one minute and then irradiated with ultraviolet light (600 mJ) toform a coating resin layer, whereby producing a conductive layered body.

COMPARATIVE EXAMPLE 3

A conductive layered body was obtained in the same manner as inComparative Example 2 except that the composition for a coating resinlayer was applied to a dried thickness of 100 nm.

COMPARATIVE EXAMPLE 4

A conductive layered body was obtained in the same manner as inComparative Example 2 except that the composition for a coating resinlayer was applied to a dried thickness of 5 μm.

COMPARATIVE EXAMPLE 5

A transfer film was produced in the same manner as in Example 1 exceptthat the composition 1 for a conductive layer was applied in an amountof 75 mg/m². Thereafter, a conductive layered body was obtained in thesame manner as in Example 1 except that the produced transfer film wasused.

The conductive layered bodies obtained in the examples and comparativeexamples were subjected to the following evaluations. Table 1 shows theresults.

(Total Light Transmittance)

The total light transmittance of each conductive layered body wasmeasured with a haze meter (HM150) produced by Murakami Color ResearchLaboratory Co., Ltd. by a method in accordance with JIS K7105.

(Haze Value)

The haze of each conductive layered body was measured with a haze meter(HM150) produced by Murakami Color Research Laboratory Co., Ltd. by amethod in accordance with JIS K7105.

(Value of Haze Derived From Conductive Fibrous Filler)

As shown in Table 1, a substrate according to Experiment Example 1 wasprepared in the same manner as the conductive layer according to theexamples, except that the substrate contained no conductive fibrousfiller. A sample 0 was prepared by bonding glass to both sides of thesubstrate using optically clear adhesive tape (OCA). The haze of thesample 0 was measured and taken as H0. Samples 1 were prepared bybonding glass to both sides of each of the conductive layers accordingto the examples and the comparative examples. The haze of each sample 1was measured and taken as H1. The haze determined by calculating H1-H0was taken as the value of the haze derived from the conductive fibrousfiller.

(Sheet Resistance Value)

For each conductive layered body, the resistance value (sheetresistance) of the surface of the conductive layer on the side oppositethe receiver was measured in accordance with JIS K7194:1994 (Testingmethod for resistivity of conductive plastics with a four-point probearray) using Loresta GP (Model MCP-T610) produced by Mitsubishi ChemicalCorporation.

(Ratio of the Conductive Material Element)

For each conductive layered body, the ratio, in atomic percentage, ofthe conductive material element (Ag) on the surface of the conductivelayer on the side opposite the receiver was measured under the followingconditions by X-ray photoelectron spectroscopy. As mentioned below, thevalue measured at a depth of 10 nm from the surface was taken as theratio of the conductive material element on the surface.

Accelerating voltage: 15 kVEmission current: 10 mAX-ray source: Al dual anodeMeasurement area: 300×700 μmφMeasurement at a depth of 10 nm from the surfaceThe average of three measurements (n=3, three random sites)

(Surface Hardness)

The surface hardness of the conductive layer of each conductive layeredbody was measured using an ultramicrohardness measuring device(PICODENTOR, Fischer) under the following conditions.

Maximum load: 40 mNLoad application: 20 sIndentation depth from the surface: 1000 nm, 100 nm, 10 nmThe average of five measurements (n=5, five random sites) for eachindentation depth

(Solvent Resistance)

For each conductive layered body, the solvent resistance of the surfaceof the conductive layer on the side opposite the receiver was evaluatedwith a Gakushin-type rubbing tester under the following conditions.

Waste cloth impregnated with IPA and waste cloth impregnated with PMAwere each mounted on a jig (1 kg/4 cm²). Each waste cloth wasreciprocated five times on the surface of the conductive layer of theconductive layered body on the side opposite the receiver. Then thesurface resistance value and the appearance were evaluated.

The five reciprocating movements were conducted at an evaluation lengthof 50 mm and a rubbing speed of 100 mm/sec. The appearance was evaluatedby reflecting light from a fluorescent lamp off the surface to visuallycheck the surface for scratches.

(Scratch Resistance)

For each conductive layered body, the scratch resistance of the surfaceof the conductive layer on the side opposite the receiver was evaluatedusing a Gakushin-type rubbing tester under the following conditions.

Waste cloth mounted on a jig (1 kg/4 cm²) was reciprocated five times onthe surface of the conductive layer of the conductive layered body onthe side opposite the receiver. The sheet resistance and the appearanceafter the five reciprocating movements were evaluated.

The five reciprocating movements were conducted at an evaluation lengthof 50 mm and a rubbing speed of 100 mm/sec. The appearance was evaluatedby reflecting light from a fluorescent lamp off the surface to visuallycheck the surface for scratches.

(Etching Suitability)

An aqueous solution of phosphoric acid, nitric acid, and acetic acid(SEA-5, Kanto Chemical Co., Inc.) was warmed to 35° C., and theconductive film was immersed therein for two minutes. The resistancevalue of the surface of the conductive layer on the side opposite thereceiver was then measured to determine the etching suitability underwet conditions.

(Bending Test)

Each of the conductive layered bodies obtained in the examples andcomparative examples was wound around a metal bar (φ4 mm) with theconductive layer surface facing outward. The sheet resistance value wasthen measured by the above method and the presence and absence of crackswas visually checked.

TABLE 1 Example 1 Example 2 Example 3 Example 4 Example 5 Example 6Example 7 Total light transmittance (%) 90.5 90.2 90.2 89.5 88 82 90.2Haze (%) 1.2 1.4 1.4 1.7 2 4.3 1.4 Haze (%) derived from conductive 0.80.9 0.9 1.2 1.4 3.5 0.9 fibrous filler Sheet resistance (Ω/□) 98 53 4539 23 5 40 Surface Ag ratio (at %) 0.4 0.47 0.47 0.98 2.05 4.95 0.47Surface hardness  at 10 nm 5620 5789 5620 5322 4992 4721 32165(PICODENTOR)  at 100 nm 323 315 323 313 301 282 953 (N/mm²) at 1000 nm43 45 43 40 38 35 93 Solvent resistance (IPA) (Ω/□) 99 53 45 40 27 5 40Solevent resistance (IPA) No change No change No change No change Nochange No change No change (appearance) Solvent resistance (PMA) (Ω/□)98 54 46 39 26 6 40 Solvent resistance (PMA) No change No change Nochange No change No change No change No change (appearance) Scratchresistance (Ω/□) 102 56 47 41 26 8 40 Scratch resistance (appearance) Nochange No change No change No change No change No change No changeEtching suitability (Ω/□) over Load over Load over Load over Load overLoad over Load over Load Bending test (Ω/□) 99 54 44 40 26 5 40 Bendingtest (cracks) None None None None None None None Comparative ComparativeComparative Comparative Comparative Experiment Example 8 Example 1Example 2 Example 3 Example 4 Example 5 Example 1 Total lighttransmittance (%) 90.2 90.5 90.5 90.5 90.5 78 92 Haze (%) 1.4 1.3 1.21.2 1.3 5.8 0.2 Haze (%) derived from conductive 0.9 0.8 0.8 0.8 0.9 4.80 fibrous filler Sheet resistance (Ω/□) 46 95 108 113 over Load 3 overLoad Surface Ag ratio (at %) 0.46 0.68 0.25 0.14 0 6.21 0 Surfacehardness  at 10 nm 5638 968 972 1019 56210 4532 5772 (PICODENTOR)  at100 nm 322 124 135 181 3152 251 330 (N/mm²) at 1000 nm 41 16 18 27 15033 44 Solvent resistance (IPA) (Ω/□) 46 over Load over Load 113 overLoad 5 over Load Solevent resistance (IPA) No change Many Many No changeNo change No change No change (appearance) scratches scratches Solventresistance (PMA) (Ω/□) 46 over Load over Load 125 over Load 5 over LoadSolvent resistance (PMA) No change Many Many No change No change Nochange No change (appearance) scratches scratches Scratch resistance(Ω/□) 46 over Load over Load 387 over Load 5 over Load Scratchresistance (appearance) No change Many Many 3 scratches No change 3scratches No change scratches scratches Etching suitability (Ω/□) overLoad over Load over Load 678 over Load over Load over Load Bending test(Ω/□) 45 96 97 114 over Load 3 over Load Bending test (cracks) None NoneNone None Presence None None

In Table 1, “over Load” means that the resistance value was greater thanmeasurable range and thus was not measurable.

As shown in Table 1, the conductive layered bodies according to theexamples were excellent in all of the total light transmittance, haze,surface hardness, solvent resistance, scratch resistance, and etchingsuitability. The conductive layered bodies according to Examples 3 to 6and 8, in which the conductive layers did not contain the binder resin,had a lower resistance value than the conductive layered bodiesaccording to Examples 1 and 2, in which the conductive layers containedthe binder resin. Here, the resistance value of the conductive layeredbody according to Example 8 is the value on the surface of the coatingresin layer. The conductive layered body according to Example 7 wasexcellent in surface hardness as compared with the conductive layeredbody according to Example 3 because of the additional ultravioletirradiation after the removal of the release film of the transfer film.

The conductive layered body according to Comparative Example 1 was poorin surface hardness, solvent resistance, and scratch resistance becauseit was produced simply by applying the conductive layer to the releasefilm. The conductive layered bodies according to Comparative Examples 2and 3, in which the coating resin layer was formed on the conductivelayer, the ratio of the conductive material element constituting theconductive fibrous filler on the surface of the conductive layer wassmall. The conductive layered body according to Comparative Example 2,which included a thin coating resin layer, was poor in surface hardness,solvent resistance, and scratch resistance. The conductive layered bodyaccording to Comparative Example 3, which included a thick coating resinlayer, was poor in surface hardness and scratch resistance, as well asin etching suitability. The conductive film according to ComparativeExample 4, which included a very thick coating resin layer, was poor insheet resistance. The conductive film according to Comparative Example 5was low in total light transmittance and in haze value (and haze derivedfrom the conductive fibrous filler) because of the application of alarge amount of the composition for a conductive layer.

INDUSTRIAL APPLICABILITY

The conductive layered body of the present invention has excellentsolvent resistance and scratch resistance, as well as a low haze valueand a significantly high light transmittance. The conductive layeredbody can be suitable for use as a transparent electrode of, for example,displays such as liquid crystal displays (LCDs), plasma display panela(PDPs), touch panels, and solar batteries, especially as a transparentelectrode of touch panels.

1. A conductive layered body comprising, as an outermost layer thereof,a conductive layer containing a conductive fibrous filler, wherein theconductive layered body has a Martens hardness of 150 to 3,000 N/mm² asmeasured at an indentation depth of 100 nm from a surface, and a ratio,in atomic percentage, of a conductive material element constituting theconductive fibrous filler on an outermost surface-side surface of theconductive layer is 0.15 to 5.00 at %.
 2. The conductive layered bodyaccording to claim 1, wherein the conductive layered body has a totallight transmittance of 80% or higher and a haze of 5% or lower.
 3. Theconductive layered body according to claim 1, wherein the conductivelayer contains a binder resin and has the conductive fibrous fillercontained in the binder resin, and part of the conductive fibrous fillerprotrudes from the outermost surface-side surface of the conductivelayer.
 4. The conductive layered body according to claim 1, wherein theconductive layer has a thickness smaller than a fiber size of theconductive fibrous filler.
 5. The conductive layered body according toclaim 1, wherein the conductive fibrous filler has a fiber size of 200nm or smaller and a fiber length of 1 μm or greater.
 6. The conductivelayered body according to claim 1, wherein the conductive fibrous filleris at least one selected from the group consisting of conductive carbonfibers, metal fibers, and metal-coated synthetic fibers.
 7. Theconductive layered body according to claim 1, wherein the conductivelayer is on a resin layer.
 8. A touch panel comprising the conductivelayered body according to claim
 1. 9. A method of producing a conductivelayered body including, as an outermost layer thereof, a conductivelayer containing a conductive fibrous filler, the method comprising atransferring step of transferring a conductive layer to a receiver usinga transfer film having at least the conductive layer on a release film.10. The method of producing a conductive layered body according to claim9, wherein a conductive layered body has a haze value of 5% or lower anda total light transmittance of 80% or higher.
 11. The method ofproducing a conductive layered body according to claim 9, wherein theconductive layer in the transfer film contains a binder resin and hasthe conductive fibrous filler contained in the binder resin, and part ofthe conductive fibrous filler protrudes from a surface of the conductivelayer on the side opposite the release film.
 12. The method of producinga conductive layered body according to claim 9, wherein the conductivelayer has a thickness smaller than a fiber size of the conductivefibrous filler.
 13. The method of producing a conductive layered bodyaccording to claim 9, wherein the conductive fibrous filler has a fibersize of 200 nm or smaller and a fiber length of 1 μm or greater.
 14. Themethod of producing a conductive layered body according to claim 9,wherein the conductive fibrous filler is at least one selected from thegroup consisting of conductive carbon fibers, metal fibers, andmetal-coated synthetic fibers.
 15. The method of producing a conductivelayered body according to 9, further comprising a treatment step ofsubjecting the conductive layer to ultraviolet irradiation and/orheating.
 16. The method of producing a conductive layered body accordingto 9, wherein the receiver is a resin layer.